Gas compressors



Dec. 27, 1966 H. E. ELLINGER ET AL GAS COMPRESSORS Filed Nov. 4, 1964 5 Sheets$heet 1 INVENTORS. 3Z2 1- v f/erber/ 5 mm 6/ BY 6 we ATTORNEY.

Dec. 27, 1966 ELLINGER ET AL 3,294,316

GAS GOMPRESSORS Filed Nov. 4, 1964 5 Sheets-Sheet 2 INVENTORS fierberf 5 er fl/ red /7. Humphrey BY @W Q AT TORNEY Dec. 27, 1966 H? G R ET AL 3,294,316

GAS COMPRESSORS 3 Sheets-sheet 3 Filed Nov. 4, 1964 W/zkgg BY. @WMF ATTORNEY United States Patent 3,294,316 'GAS CUMPRESSORS Herbert E. Eliinger and Alfred H. Humphrey, Kalamazoo, Mich, assignors to General Gas Light Company, Kalamazoo, Mich.

Filed Nov. 4, 1964, Ser. No. 498,921 13 Claims. ((31. 230-187) This invention relates to improvements in gas compressors. The principal objects of this invention are:

First, to provide a compressor which has a high volume and pressure capacity in a minimum of compressor structure.

Second, to provide a compressor in which a plurality of elongated pressure chambers of rectangular cross-section are disposed in radially projecting relation around a central opening in which a drive shaft with pump element actuating eccentrics is rotatably positioned and in which the pump elements are positively retracted on the intake stroke by a novel arrangement of retracting links connecting the several pump elements.

Third, to provide a compressor of the type described which is easily and economically manufactured particularly with respect to accurate formation of the elongated pressure chambers by having the chambers formed completely through the body of the compressor from end to end and closed at the ends by end plates and members which support the drive shaft and form the inlet and outlet passages from the pressure chambers.

Fourth, to provide a compressor having a multiplicity of radially arranged pressure chambers which can be mounted vertically on end and which has external cooling fins over which air is circulated by a fan rotated by the compressor drive shaft and in which the fins may be enclosed by a shroud for effectively directing the cooling air over the fins.

Fifth, to provide a compressor having radially arranged axially extending pumping elements and chambers disposed around a central drive shaft and driven outwardly in pumping relation by a simple circular eccentric but in which the pumping elements are retracted more slowly than they are advanced by the eccentric so as to draw in a charge of air or gas at slower speeds thus reducing the back load on the compressor as a whole.

Sixth, to provide a compressor having a multiplicity of radially arranged pumping elements and pressure chambers in which the pumping elements are advanced in pumping action by a simple circular eccentric but in which the pumping elements are retracted by links connected to a common oscillating ring disposed around the drive shaft so that the extension of one or more of the pumping elements by the eccentric act-uates the ring and connecting links to retract other pumping elements at a different rate than the rate of advance of the pumping elements.

Other objects and advantages of the invention will be apparent from a consideration of the following description and claims. The drawings, of which there are three sheets, illustrate a highly practical form of the compressor.

FIG. 1 is a fragmentary vertical cross sectional view through the compressor taken along the plane of the angled line 15- 1 in FIGS. 2 and 4.

FIG. 2 is a fragmentary end elevational view of the body of the compressor illustrating the arrangement of the pressure chambers and cooling fins and the entrance ports to the pressure chambers.

FIG. 3 is an enlarged fragmentary vertical cross sectional view showing in greater detail the connection between the drive shaft and eccentric and the pumping ele- Patented Dec. 27, 1966 'ice ments and pump element retracting structure shown in FIG. 1.

FIG. 4 is a fragmentary trans-verse cross sectional view taken along the plane of the line 4-4 of FIG. 1 illustrating the relationship of the several pump elements and pump element retracting mechanism of the compressor.

The form of the compressor illustrated in FIGURES 1 to 4 consists of a central body indicated generally at 1 and having a central shaft and eccentric receiving opening or bore 2 formed through the center thereof. The body is generally circular and has a plurality of axially extending cooling fins 3 formed around its surface. Within the body 1 there are formed six equiangularly spaced radially projecting pressure chambers 4 of rectangular cross section which extend from end to end of the body and open inwardly to the central passage 2. At the outer side of each pressure chamber 4 there is a radially projected boss or extension 5 having an axially extending passage 6 formed therein extending to a circular boss 7 within which a check valve assembly indicated generally by the numerals 171 and 8 is positioned. The upper end passages 6 may be designated as inlet passa es and the valve assemblies 171 as inlet check valves which open inwardly to the respective pressure chambers through ports 9 while the lower axial passages 10 which extend to the check valves 8 may be considered as exhaust passages with the check valves 8 opening upwardly from outlet passages 11. However, the positions of the inlet and outlet passages and check valves can readily be reversed as will be understood.

Each end of the body 1 has a central raised shoulder 12 around the central passage or bore 2 which center an upper end plate 13 and a lower end plate 14- on the ends of the body in closing relation to the radial pressure chambers 4. The upper plate 13 has ports IS formed therein and opening to the inlet passages 6 to the inlet check valves of each pressure chamber. The lower end plate 14 has ports .16 formed therein opening correspondingly to the exhaust passages :10 from each of the pressure chambers.

Secured to the top of the top end plate 13 is a top end member 17 desirably formed as a casting and having cooling fins 18 projecting therefrom. The top end member 17 has a centering neck 19 that extends into the central opening in the top end plate and defines an annular inlet passage 20 communicating with all of the ports 15 in the top end plate. A radially extending boss 21 formed on the top end member provides an inlet connection 22 to the compressor. Positioned within a central opening in the top end member is a bearing box or bushing 23 having a roller bearing 24 mounted therein for rotatably supporting the upper journal end 25 of a crank shaft indicated generally at 26. The bearing 24 is retained in place by a snap ring 2 7 and the shaft 25 projects upwardly through a suitable seal 28 to a counterweight 29 keyed to the upper end of the shaft. Beyond the counterweight the shaft is provided with a propeller-like fan 3% for directing air downwardly around the top end member and the pump body. Desirably a cylindrical shroud 31 surrounds the fan blade and the fins 3 of the compressor body in spaced relation to obtain good heat transfer circulation of air around the outside of the compressor.

The bottom end plate 14 receives a centering neck 32 on a lower end member 33 which is similar to the upper end member 17. The lower end member 33 defines an annular exhaust or outlet passage 34 communicating with each of the outlet openings 16 in the lower end plate and with a radially extending boss 35 forming an exhaust connection 36 from the compressor. The lower end member receives a cylindrical bearing cage or bushing 3-7 within which is mounted a roller bearing 38 rotatably supporting the lower journal portion 39 of the crank shaft. The bearing 38 is retained in position by a snap ring 40 and the lower end of the shaft extends through a suitable lubricant seal 41 and through an opening in the center of a chambered mounting base 42. Within the base 42 the shaft 26 is provided with a second eccentric counterweight 43 and the shaft extends downwardly to a suitable driving means not illustrated.

Within the base 42 the shaft 26 is provided with a pulley 44 driving the belt 45 and a pulley 46 on a upright shaft 47 mounted in suitable bearings on the side of the base. The shaft 47 drives a lubricant pump 48 which draws lubricant from a reservoir tank 49 through the pipe 50 and delivers lubricant through the pipe 51 to lubricating passages 52 formed in the upper bearing block or cage 23. These passages deliver lubricant to the upper bearing 24 from where the lubricant falls along the crank shaft and the mechanism within the body of the compressor to the lower bearing 38. Lubricant is returned from the lower end of the compressor through a passage 53 in the lower end plate to the return pipe 54 to the reservoir. The end plates, end members and base of the compressor are secured together by cap screws 551 and 561 passed into tapped holes 571 in the ends of the body 1.

Turning now to the structure within the compressor body it will be noted that each pressure chamber 4 has a rigid elongated generally rectangular pumping element 55 radially reciprocably mounted therein. The pumping elements are desirably formed as castings and have peripheral flanges 56 which slidably and sealingly engage the side and end walls of the pressure chambers 4. The outer faces of the pumping elements carry rubber or other deformable sealing plates or gaskets 57 held in place by retaining plates 58 and rivets 59 (see FIG. 3). Inwardly from the upper and lower ends of the pumping elements the elements are provided with longitudinally spaced pairs of inwardly projecting ears or flanges 60 which project inwardly beyond the inner edges of the side flanges 56 and define aligned holes for receiving the cross pins 61. Between the flanges 60 the pins rotatably support rollers 62 which are in constant rolling engagement with circular eccentrics 63 formed on the crank shaft 260. In order to obtain sufficient throw for the eccentrics 63 the inner wall of the bore 2 of the casting may be notched outwardly as at 64. As the point of maximum eccentricity of the eccentrics 63 advance angularly around the inside of the compressor the rollers 62 and the pumping elements 55 are progressively forced outwardly in a pumping and gas displacing action in the pressure chambers 4.

In order to retract the pumping elements 55 and draw air or gas in through the inlet check valves 9, the pins 61 are projected outwardly beyond the supporting flanges 60 to receive the radially outer ends of link members 65. The link members have thickened bearing portions rockably or relatively rotatably mounted on the pins 61 and reduced or L-shaped inner portions 66 which support the inner ends of pivot pins 67. The outer ends of the pins 67 are supported by end plates or straps 68 fitted over the pins 67 and the ends of the pins 61 and retained in place by snap rings 69 and 70. The pins 67 each support a roller 71 which are positioned closely adjacent the crank shaft 25. The crank shaft 25 has short eccentric portions 72 at the axially outer sides of the drive eccentrics 63 to clear the rollers 71. Between the drive eccentrics 63 the crank shaft may be formed with an integral offset counterweight portions 73.

Surrounding all of the rollers 71 at each end of the pumping elements and retained between the L-shaped portion 66 of the retracting links and the retaining plates 68 is a ring 74, the inner diameter of which is sized to engage the outer periphery of a roller 71 when the pumping element to which that roller is connected is in extreme extended position by the drive eccentric 63 and also engage the radially outer side of the roller 71 on the opposite pumping element so that extension of one pumping element to its extreme position pulls the opposite pumping element inwardly in a retracting motion to draw air or gas into the opposite pumping chambers. With particular reference to FIG. 4 it will be seen that the pivotal connections between the retracting'links 65 and the pins 61 on the inner sides of the pumping elements together with the freely rolling and rockable engagement between the rollers 71 at the inner ends of the retracting links and the inside of the retracting ring 74 permit the retracting links to rock or swing between truly radial positions relative to the axis of the crank shaft 25 and inclined positions relative to radii passed through the pressure chambers 4. Thus when the lower pumping element 55 is in extreme extended position and the upper pumping element is in the extreme retracted position the retracting links will be aligned radially with the corresponding pressure chambers along an axis passing through the center of the crank shaft and the center of the driving eccentrics 63 but the intermediate retracting links will be at different angles relative to the radial axes of the pressure chambers and pumping elements. Outward pumping action of the umping element is accomplished progressively in a regular sine wave motion by the circular eccentrics 63 but the retracting motion of the pumping elements does not follow the same sine wave motion as the pumping strokes. The retracting ring 74 oscillates within the central bore 2 with the combined outward motion of the pumping elements which are being progressively extended but the retracting links of these pumping elements lag behind the rotary motion of the driving eccentrics 63. At the same time the retracting links of these pumping elements on the intake stroke swing ahead of the rotary motion of the driving eccentrics without pulling their associated pumping elements inwardly at the same rate as the rotation of the crank shaft. As a result the retracting motion of the pumping elements starts relatively slowly and builds to a maximum at the fully retracted position shown at the top of FIG. 4. This permits the intake of air or gas into the pressure chambers to begin gradually and be accelerated rather than to start with a rapid high velocity intake which would require additional power. The result is that less power is required to draw in the charge of air or gas and more of the power applied to the crank shaft is available for compressing the gasses on the advancing stroke of the pumping elements.

FIGURES 5 and 6 illustrate a modification or variation of the retracting link arrangement of the compressor. The compressor body 1A is provided with similar pressure chambers 4 and a similar crank shaft 26 having driving eccentric 63 as in the first form of the compressor. Pairs of inwardly projecting ribs or flanges 60 and 60A on the pumping elements 55A support pins 61A on which the rollers 62 for extending the pumping elements are rotatably mounted. These rollers 62 coact with driving eccentric 63 as in the first form of the compressor but the flanges 60A project radially inwardly further than the flanges 60 and support pins 161 which project toward the ends of the pumping elements and have bearings 162 mounted thereon which engage the inner periphery of an orbiting retracting ring 74A. The ring 74A is retained on the pins 161 by a snap ring 163 engaged in notches in the outer ends of the pins. The action of the modified form of compressor is similar to that obtained in the first form of the compressor except that the retarding motion of the pivoted retracting links 65 is omitted. The compressor in FIGS. 5 and 6 has somewhat fewer parts than the first form of the compressor and will be less expensive to manufacture and assemble. Where necessary the inside of the compressor body may be grooved as at 164 to provide clearance for the orbiting, retracting ring 74A as well as for the driving eccentrics 63.

What is claimed as new is:

1. A compressor having an elongated hollow body with radially disposed pump chambers extending from end to end thereof and opening at their radially inner sides to the interior of the body, 7

end members closing the ends of said chambers and rotatably supporting a shaft through the center of said body,

elongated rigid pumping elements slidably and sealingly mounted and positioned in said chambers, pairs of inlet and outlet check valves mounted in the exterior of said body and communicating between the outer sides of said chambers and axial passages formed in the body and extending to an end thereof,

and eccentrics on said shaft within said body in radially driving engagement with the inner sides of said pumping element,

characterized by said pumping elements having inwardly projecting ribs transverse to said chambers and said shaft,

pins supported on said ribs and having bearings thereon rollingly engageable with said eccentrics,

links connected to said flanges and extending swingably towards said shaft,

second hearings on the radially inner ends of said links,

pump element retracting rings surrounding the radially outer sides of said second hearings on all of said links and surrounding said shaft,

and a drive connection on said shaft external to one of said end members.

2. A compressor as defined in claim 1 in which said end members consist of plates centered around shoulders on the ends of said body,

and end caps clamped to said plates with anti-friction bearings mounted in said end caps and rotatably supporting the ends of said shaft' 3. A compressor as defined in claim 2 in which said end caps have annular passages formed in their inner faces closed by said plates,

and with radially outwardly extending passages communicating with openings formed through said plates to passages formed in said body,

said passages in said body communicating with said check valves,

there being inlet and outlet connections formed one in each of said caps and communicating with said annular passages.

4. A compressor as defined in claim 3 in which said body is mounted on one end and said shaft has a cooling fan mounted on its other end exteriorly of one of said end caps,

and a shroud extending in spaced relation around said body to receive air circulated by said fan,

said shroud having openings formed therein at the opposite end thereof from said fan to pass air through said shroud and along the outside of said body.

5. A compressor as defined in claim 4 in which said body has external cooling fins projecting therefrom within said shroud.

6. A compressor as defined in claim 5 in which said body and shaft are mounted upright on a recessed base,

an oil reservoir mounted in said base and communicating with the lower end of the interior of said body,

and a pump mounted on said base and driven from said shaft and delivering from said reservoir to the bearing in the upper of said end caps.

7. A compressor as defined in claim 6 in which said ribs on said pumping elements are arranged in pairs with said pins supported therebetween,

and said bearings on said pins are rollers rotatably mounted on the pins,

said pins projecting beyond one rib of said pairs of ribs,

said links having hubs rockably mounted on the ends of said pins,

other pins projecting from the inner ends of said links,

and retaining strips secured to the ends of first pins to retain said links thereon and secured to the ends of said second pins,

said hearings on the inner ends of said links being rollers retained on said second pins by said retaining strips.

8. A compressor as defined in claim 1 in which said ribs on said pumping elements are arranged in pairs with said pins supported therebetween,

and said hearings on said pins are rollers rotatably mounted on the pins,

said pins projecting beyond one rib of said pairs of ribs,

said links having hubs rockably mounted on the ends of said pins,

other pins projecting from the inner ends of said links,

and retaining strips secured to the ends of first pins to retain said links thereon and secured to the ends of said second pins,

said bearing on the inner ends of said links being rollers retained on said second pins by said retaining strips.

9. A compressor as defined in claim 1 in which said passages in said body extend from said inlet valves to one end and from said outlet valves to the other end of the body,

said end members having annular passages formed in their inner sides communicating with the ends of said chambers and each having an external connection to said passages.

16'. A compressor as defined in claim 1 in which said shaft has a drive section projecting beyond one end member,

a fan secured to the opposite end of the shaft beyond the other end member,

and cooling fins on the exterior of said body extending axially of the body.

11. A compressor as defined in claim 10 in which said fan and said fins are surrounded by a tubular shroud wit-h outlet openings at the opposite end from the fan.

12. A compressor comprising a tubular body having axially extending and radially spaced pressure chambers formed therein in angularly spaced relation and opening radially inwardly of the body,

a drive shaft rotatably supported on an axis concentrically through said body,

elongated rigid pumping elements slidably and sealingly reciprocable in radial directions in said chambers, eccentric means on said shaft simultaneously engageable with the radially inner sides of said pumping elements at longitudinally spaced points therealong,

pairs of pumping element retracting links having radially outer ends pivotally connected to the inner sides of said pumping elements at longitudinally spaced points therealong,

means forming radially outwardly bearing surfaces on the radially inner ends of said links,

and pairs of retracting rings embracing said shaft and simultaneously engaging said bearing surfaces along the radially inner sides of said rings,

said chambers opening through inlet and outlet check valves to common inlet and outlet passages.

13. A compressor comprising a tubular body having axially extending and radially spaced pressure chambers formed therein in angularly spaced relation and opening radially inwardly of the body,

a drive shaft rotatably supported on an axis concentrically through said body,

elongated rigid pumping elements slidably and sealingly reciprocable in radial directions in said chambers,

eccentric means on said shaft simultaneously engage- References Cited by the Examiner able With the radially inner sides Of said pumping UNITED STATES PATENTS elements, pumping element retracting links having radially outer u ends pivotally connected to the inner sides of said 5 2570134 10/1951 Lancaster Pumpmg l 2,660,365 11/1953 Paget 230 1s7 means forming rad1ally outwardly bearing surfaces on 2,668,004 2/1954 Browne 230 187 the radially inner ends of said links,

FOREIGN PATENTS and a retracting ring embracing said shaft and simultaneously engaging said bearing surfaces along the radially inner side of said ring, I

said chambers opening through inlet and outlet check MARK NEWMAN valves to common inlet and outlet passages. R. M. VARGO, Assistant Examiner.

10 893,293 10/1953 Germany. 

1. A COMPRESSOR HAVING AN ELONGATED HOLLOW BODY WITH RADIALY DISPOSED PUMP CHAMBERS EXTENDING FROM END TO END THEREOF AND OPENING AT THEIR RADIALLY INNER SIDES TO THE INTERIOR OF THE BODY, END MEMBERS CLOSING THE ENDS OF SAID CHAMBERS AND ROTATABLY A SHAFT THROUGH THE CENTER OF SAID BODY, ELONGATED RIGID PUMPING ELEMENTS SLIDABLY AND SEALINGLY MOUNTED AND POSITIONED IN SAID CHAMBERS, PAIRS OF INLET AND OUTLET CHECK VALVES MOUNTED IN THE EXTERIOR OF SAID BODY AND COMMUNICATING BETWEEN THE OUTER SIDES OF SAID CHAMBERS AND AXIAL PASSAGES FORMED IN THE BODY AND EXTENDING TO AN END THEREOF, AND ECCENTRICS ON SAID SHAFT WITHIN SAID BODY IN RADIALLY DRIVING ENGAGEMENT WITH THE INNER SIDES OF SAID PUMPING ELEMENT, CHARACTERIZED BY SAID PUMPING ELEMENTS HAVING INWARDLY PROJECTING RIBS TRANSVERSE TO SAID CHAMBERS AND SAID SHAFT, PINS SUPPORTED ON SAID RIBS AND HAVING BEARINGS THEREON ROLLINGLY ENGAGEABLE WITH SAID ECCENTRICS, LINKS CONNECTED TO SAID FLANGES AND EXTENDING SWINGABLY TOWARDS SAID SHAFT, SECOND BEARINGS ON THE RADIALLY INNER ENDS OF SAID LINKS, PUMP ELEMENT RETRACTING RINGS SURROUNDING THE RADIALLY OUTER SIDES OF SAID SECOND BEARINGS ON ALL OF SAID LINKS AND SURROUNDING SAID SHAFT, AND A DRIVE CONNECTION ON SAID SHAFT EXTERNAL TO ONE OF SAID END MEMBERS. 